A tonoscope is a tube you sing into, with a membrane stretched over the far end and powder on the membrane. Hum a steady note and the powder arranges itself. This one is a plastic cup, a balloon for the membrane, a straw to hum through and salt for the medium — no electronics at all, because the voice is the driver.
The demonstration is by Leeyah Lavallais, a ninth grader from St. Mary's Academy, filmed for a FOX 8 New Orleans segment with host Rob Krieger. The video runs just under five minutes and stays at the level of a broadcast science slot rather than a build tutorial, so expect the phenomenon rather than the engineering.
It is a good corrective to rig envy. A voice-driven membrane is how Margaret Watts Hughes worked in the 1880s, and it still produces the effect without a speaker anywhere in the chain.